Big integrals, opApply autoindex, safer integrals

[Yigal Chripun]

Weed wrote:
> Yigal Chripun пишет:
>> Weed wrote:
>>> bearophile пишет:
>>>> Weed:
>>>>> where else can I use that thing?
>>>> I was talking about a built-in syntax for multi-precision integral
>>>> numbers. I presume you can use it only when you want to use
>>>> multi-precision integral number :-)
>>>> Do you feel the need to use it in other situations too?
>>> I thought proposes a more advanced method for operators overloading :)
>>>
>>> It seems to me, all operators working with values should correspond to
>>> processor instructions. Instruction like "Sum int [80] with int [30]"
>>> does not exist and it is not necessary to do for it the built-in-like
>>> syntax.
>> I disagree. Programing languages are for programmers, i.e Humans, not
>> CPUs. if you want to work with a programming language that corressponds
>> to a CPU, go learn Assemby language.
>>
>> It makes perferct sense to use operators that do not corespond to cpu
>> instructions, for example:
>> auto m1 = new Matrix(10, 30);
>> auto m2 = new Matrix(30, 20);
>> ... fill m1, m2 with data...
>> auto res = m1 * m2;
>>
>
> Ohhh! Matrices! Mmmm... :)
>
>> The point of programming languages is to provide abstarctions to the
>> underlying machine,
>
> without the overhead!
>
>> so that we humans can express complex problems to
>> the CPU more easily.
>
> Yes. But language without the overhead costs almost get what I said.
>
>> also, another reason for allowing: "Sum int [80] with int [30]" is due
>> to vectorization. modern CPUs can perform operations on vectors so
>> instead of doing:
>> for (int i = 0; i<  80; ++i) { sum[i] = a[i] + b[i] }
>> the CPU can process those in chunks of 4 ints at a time or something
>> like that. This is already implemented in DMD.
>
> int[80] there is not an array of type int, it very big 80 bit int value
>
>
> So initialization of mathematical types at compile time would be more
> interesting:)

sorry, I don't understand your english.
int[80] is an array. see:
auto a = int[80];
personally I'm against your idea of using static data as this is thread 
unsafe.
D2 will have shared to deal with multi-threading issues like that. 
still, I'd say that static should be limited to invariant data.
it makes sense to do:
static invariant m = IdentityMatrix(3,5);
for instance, but what's the benefits of doing the same for mutable 
data? I don't see it..